Ordinarily a good way to end an essay is with a pertinent quote, especially if it is from a distinguished source like Ralph Waldo Emerson, who always seems to have said something impressive. It is a good practice to save quotes in a file where you can retrieve them easily. Otherwise, you may waste a lot of time trying to find the quote you want and possibly never being able to find it again.
In your case, however, since you are a law student and are apparently writing a law paper, my feeling is that ending with a quote would be inappropriate because it might sound too "literary" and not sufficiently legalistic. You would probably make a better impression on the reader if you ended with a statement of your own opinion and one which would sum up what you have already stated.
I guess there is no rule against closing a legal paper with a quotation, but my intuition tells me it might be better to avoid it.